摘要:
An alloy comprising: a magnetostrictive iron alloy having the formula: FexGayAlz, where x is of from about 65 at % to about 90 at %, y is of from about 5 at % to about 35 at %, and z is of from about 0 at % to about 30 at %; and wherein said alloy has a room temperature magnetostriction of at least approximately 150 ppm. An alloy having a saturated magnetostriction of from about at least 150 ppm comprising: a magnetostrictive iron alloy having the formula: FexGayBet, where x is of from about 65 at % to about 90 at %, y is of from about 1 at % to about 35 at %, and t is of from about 1 at % to about 30 at %; and wherein said alloy has a room temperature magnetostriction of at least approximately 150 ppm.
摘要:
Disclosed are bimetallic strips that incorporate magnetostrictive materials to enhance and provide sensing, actuating and energy harvesting functions. The bimetallic strips include a positive magnetostrictive Fe-based alloy layer and a flexible layer. The flexible layer may be a negative magnetostrictive layer or a permanent magnet layer. One or more permanent magnet materials may also be used in the arrangement. The bimetallic strips are inexpensive and easily manufactured, and have characteristics that enhance sensing and actuator applications, and enables energy harvesting.
摘要:
A magnetostrictive element having a large magnetomechanical coupling factorlong its axis, is selected to determine strain by measurement of changes in its electrical impedance along such axis. Such measurement is maximized by generation of current of a predetermined frequency conducted through the magnetostrictive element to correspondingly penetrate the magnetostrictive element to a substantial skin depth.
摘要:
A method of using a magnetostrictive material to achieve a high magnetomechanical coupling factor comprising building an internal anisotropy energy into the magnetostrictive material and applying a tensile or compressive stress to the magnetostrictive material with the built-in internal anisotropy energy. The internal anisotropy energy is built into the magnetostrictive material by annealing the magnetostrictive material under an annealing stress or a suitable magnetic field. For a positive magnetostrictive material, when the annealing stress is compressive, the stress applied to the annealed material under operation is tensile, and when the annealing stress is the tensile, the stress applied to the annealed material under operation is compressive. For a negative magnetostrictive material, when the annealing stress is compressive, the stress applied to the annealed material under operation is tensile, and when the annealing stress is tensile, the stress applied to the annealed material under operation is compressive.
摘要:
The efficiency of converting electrical energy into a mechanical output is maximized by alternatively matching selection of power supply for the drive coil applying a magnetic field to transducer element made of a magnetostrictive material having a near-zero magnetic anisotropy, or matching selection of the magnetostrictive material to the required magnetostriction for a given power supply.
摘要:
Magnetostrictive material such as Terfenol-D undergoes annealing treatmenty heating for a limited period of time to an elevated temperature below the melting point, followed by cooling to a preferred magnetic state in which a compressive stress generated and applied during treatment is retained in the treated material as a built-in prestress.
摘要:
Disclosed are bimetallic strips that incorporate magnetostrictive materials to enhance and provide sensing, actuating and energy harvesting functions. The bimetallic strips include a positive magnetostrictive Fe-based alloy layer and a flexible layer. The flexible layer may be a negative magnetostrictive layer or a permanent magnet layer. One or more permanent magnet materials may also be used in the arrangement. The bimetallic strips are inexpensive and easily manufactured, and have characteristics that enhance sensing and actuator applications, and enables energy harvesting.
摘要:
An elongate structure having a magnetostrictive material composition is subjected to tensile stress in the longitudinal-axial direction, thereby generally orienting the magnetization of the elongate structure in the longitudinal-axial direction. Electrical current is conducted through the elongate structure and/or through at least one adjacent elongate conductor, thereby generally orienting the magnetization of the elongate structure in the transverse direction, generally in parallel with the transverse direction of the magnetic field concomitant the conduction of current through the elongate structure. The elongate structure magnetostrictively contracts due to the (generally 90°) repositioning of the magnetization of the elongate structure. Examples of inventive configurational variants include: (i) an elongate structure itself conducting current; (ii) a hollow elongate structure accommodating placement therethrough of at least one elongate conductor; (iii) an elongate structure flanked by a pair of elongate conductors conducting current in opposite directions; (iv) plural elongate structures bordering a centralized elongate conductor.
摘要:
A positive magnetostrictive material such as a ferromagnetic alloy is subjected to a magnetic field during annealing treatment while being heated for a predetermined period of time at an elevated temperature below its softening temperature followed by cooling resulting in a treated ferromagnetic material having high tensile strength and positive magnetostriction properties for enhancing use thereof under tensile loading conditions. Such treatment of the ferromagnetic alloy may be augmented by application thereto of a compressive stress.